21444546 has 8 divisors (see below), whose sum is σ = 42889104. Its totient is φ = 7148180.

The previous prime is 21444541. The next prime is 21444581. The reversal of 21444546 is 64544412.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

21444546 is an admirable number.

It is a super-2 number, since 2×21444546² = 919737106292232, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21444541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1787040 + ... + 1787051.

It is an arithmetic number, because the mean of its divisors is an integer number (5361138).

Almost surely, 2^21444546 is an apocalyptic number.

21444546 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21444546 is a wasteful number, since it uses less digits than its factorization.

21444546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3574096.

The product of its digits is 15360, while the sum is 30.

The square root of 21444546 is about 4630.8256283302. The cubic root of 21444546 is about 277.8256156662.

Adding to 21444546 its reverse (64544412), we get a palindrome (85988958).

The spelling of 21444546 in words is "twenty-one million, four hundred forty-four thousand, five hundred forty-six".